Our primary research effort is to determine the precise lower molecular weight water soluble proteins (LMW-sol) and protein-protein interactions that lead to the formation of water soluble and insoluble protein aggregates (HM-sol and HM-insol) in aging normal and nuclear sclerotic human cataractous lenses. For this purpose, we are analyzing the molecular size distribution, concentration variation, charge distribution, amino acid composition, and subunit composition of the components of LMW-sol separated from infant, adult, senile and nuclear sclerotic cataractous lenses. A parallel study on the amino acid composition, subunit molecular weight, and subunit charge distribution of adult normal and cataractous lens HM-sol and HM-insol proteins is being performed. The information obtained through these studies will be used to quantitatively and qualitatively compute the proteins and protein combinations that lead to aggregate formation, hence, opacification in the human lens.